Here is my Issue, My 88 F-250 starts up great when its cold , It been 1F snow and ice, Fires up in two seconds flat. When the engine is hot it takes a longer time to crank over and blows out black smoke. At some times during light speeds like 50- 65mph when I accelerate it will also puff out dark black smoke, but not when I'm doing 75mph and accelerate. My Tail Pipe is coated in black soot as is my bumper, the pipe used to be just rusty. THe O2, Spark Plugs, cap & rotor, Map, Fuel filter are all new. Could this Be a Fuel Regulator Problem or IAC? Perhaps my Injectors are going bad? I have used different top brand fuel injector cleaners to no avail. Again it starts great when then engine is cold, in two seconds flat it will fire up, when the engine is hot, it takes longer and it blows out a puff of black smoke. Well thanks guys for any feedback.

 

how much oil is it using ? my 89 f-350 has a bad intake (i believe the gasket area is warped ) it sounds like what my truck does . no.7 intake port has oil in it ,fouls no.7 plug.smokes tail pipe full of black soot . not saying the exact problem ,maybe rings are getting bad. how many miles? that would be my guess. maybe some place to start.

 

Funny, my #7 was oily too, the rest are white. Before I had replaced my Plugs I regaped them and that #7 plug was fouled. I replaced it with a spare, but later when I replaced them all it was clean. Oil, it uses oil about a quart every couple weeks, it was leak in pan gasket. Miles, it has 106,000.

 

mine has 180,000 on it .i picked up a whole motor so i could swap intakes but just haven't had the money yet! thats just one minor project on that truck .but i think the intake is warped .that was my first thought on yours but it could be fuel related. another thought might be valve seals leaking but that would show up on the plugs i would think

 

Had same prblm with 93 bronco turned out fp reg diaghram was screwed pulled vacume hose off seen it was pumpin raw full directly in intake plenum replaced reg prob solved,hope this helps!

 

Oil smoke is blue not black. Too much fuel is black and you have to much fuel getting into the engine. Either leaking injectors and bad fuel pressure regulator or the computer getting bad inputs and telling the engine to run rich, like the temp sender telling the computer the engine it is always cold and doesn't warm up. Run the codes and see what you get. Oh and check the fuel pressure.